Antiperspirants and deodorants are sold in various forms such as gels, solids, roll-ons, and aerosols. Gels are currently popular, since they often are perceived by consumers to have certain advantageous properties such as smooth application and cool, comfortable feel when applied to skin. In addition, when the gels are clear, they are perceived to be cleaner and less apt to stain clothing.
Antiperspirants and deodorants in the gel form are well known in the art. Typically, these gels are in the oil in water emulsion form and contain water and a gellant in addition to other ingredients such as emulsifiers and emollients. Commonly used gellants are dibenzylidene alditols. For example U.S. Pat. No. 4,518,582 teaches acid stable monosorbitol gels which contain a mixture of solvents, dibenzylidene monosorbitol acetal as a gellant, C.sub.12-20 fatty acids, and a gel stabilizer which is a mixture of magnesium sulfate, zinc acetate, and hexamethylene triamine.
Sodium stearate is also a well known gellant, and is often used in deodorant. For example, PCT WO 97/14398 teaches soap based, clear gel antiperspirant compositions containing 2 methyl 1,3-propanediol. However, sodium stearate tends to react with antiperspirant salts so it is difficult to make sodium stearate based antiperspirant gel compositions.
U.S. Pat. No, 5,587,153 teaches clear gel water in oil emulsion antiperspirant compositions based upon water in silicone emulsions. However, these gels show problems with stability and syneresis.
Agarose and certain other polysaccharides such as gellan gum, carageenans, and the like, are well known gellants and are readily available. However, polysaccharides in general are very unstable in the presence of antiperspirant salts and quickly lose their gelling capabilities when exposed to such salts. Further, including other ingredients in the gel composition to enhance the commercial properties of the gel causes even further instablity, which results in syneresis and other problems which make such products commercially unacceptable.
WO 95/31967 teaches that polysaccharides such carageenans or gellan gum can be used to make antiperspirant gels if the polysaccharide gel is kept removed from the aqueous antiperspirant salt solution via formation of a triple emulsion. In particular, the aqueous antiperspirant salt solution is dispersed in an oil phase. This water in oil emulsion is then dispersed in a gelled aqueous outer phase, which isolates the antiperspirant salt from the gelled phase. This process is disadvantageous because of the preparation of the triple emulsion is tricky and time consuming. In addition, the emulsion itself may not be as stable as desired.
There is a need for an gel composition made from polysaccharides which is stable in the presence of antiperspirant salts, i.e. does not precipitate or exhibit unacceptable levels of syneresis.
An object of the invention is to formulate a single phase gel composition containing polysaccharide gellants.
An object of the invention is to formulate a single phase gel composition containing polysaccharide gellants, which is stable in the presence of antiperspirant salts, i.e. the gel does not precipitate out of the composition and the composition does not exhibit unacceptable levels of syneresis.
Another object of the invention is to prepare a clear or translucent single phase gel composition containing polysaccharides. Another object of the invention is to prepare an opaque gel composition containing polysaccharides.
Another object of the invention is to prepare a gel composition containing polysaccharide gellants suitable for use as an antiperspirant or deodorant stick or soft solid.
Another object of the invention is to provide a method for making a solid gel antiperspirant/deodorant composition which is stable.